Abstract
Background: Over the last decades, the application of mucoadhesive polymers in nasal drug delivery systems has gained interest among pharmaceutical scientists as a means of promoting dosage form residence time in the nasal cavity as well as improving intimacy of contact with absorptive membranes of the biological system. In addition, the enhanced paracellular absorption following the swelling of the mucoadhesive polymers on the nasal membranes provides an important way for the absorption of the macromolecules through the nasal cavity. Method: This paper describes some aspects of mucoadhesion related to the nasal drug delivery system. First the theories of the adhesion of mucoadhesive polymers to the mucosa epithelium are described. Then the characteristics and application of several widely used polymers in nasal drug delivery are presented. Finally, the influences of dosage form on the nasal absorption of drugs in the mucoadhesive polymer-based formulations are discussed. Conclusion: The mucoadhesive polymers have enormous potential for the delivery of therapeutic macromolecules, genes, and vaccines through the nasal cavity with high drug bioavailability.